如何使用MySQL查询查找表中最后插入的varchar值

Question

I have a table student , table structure is follow

student_id | name | class|
-------------------------
2-12-2013 | test | 3    |
-------------------------
2-13-2013 |test2 | 5    |
-------------------------

in this table i want add new record, its student_id become 2-14-2013 . For that i want to get the last inserted student_id. how can i get it by MySQL query . Am alredy use mysql_insert_id() But its not working, How to solve this issue?

Answer 1

Define Your student table like below:-

student_id | add_date  | name | class|
--------------------------------------
1          | 2013-12-2 | test | 3    |
--------------------------------------
2          | 2013-13-2 |test2 | 5    |
--------------------------------------

student_id would be int auto increamented primary key

then execute Query like below to get last inserted id:-

select student_id from student order by student_id desc limit 1;

Answer 2

Hi You has to set primary key to your table as integer auto-increment then you can use this last inserted id

$con = mysql_connect("localhost", "root", "", "chirag2");
$sql = "INSERT INTO test_student ( student_id,name,class)values('3-12-2013','test1','3' )";
$res = mysql_query($con, $sql);

echo mysql_insert_id($con);
die;

Note: you need to truncate table before alter it and set new primary key to it so take backup before this